Cellulose-ether solvent and composition



Patented May 2%, llQZd.

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EDWARD S. FARROW, 33a, OF ROCHESTER, NEW YORK, ASSIGNOR TO EASTMAN KODAK COMEANY, OF ROCHESTER, NEW YORK, A CGRPOEATION OF NEW YORK.

CELLULOSE-ETHER SOLVENT AND CQMPOSITION,

No Drawing.

To all whom it may concern:

Be it known that I, EDWARD Jr, a citizen of the United States of America,.residing at Rochester, in the county of Monroe and State of New York, have invented certain new-and useful Improvements in Cellulose-Ether Solvents and Compositions, of which the following is a full, clear, and exact specification.

This invention relates to, solvents for making stron fiowable solutions of cellulose ether and also relates to the cellulose ether compositions produced by the aid of such solvents.- One object of my invention is to provide a solvent which will dissolve large proportions of cellulose ethers and at the same time yield solutions having a regulated viscosity for use in plastic and film making arts. Another object of my invention is to provide a cellulose ether solution, which has a regulated viscosity, for making strong, flexible, transparent film 'on the machines and by the methods known in the art.

lln U. S. Patent No. 1,188,37 6, Lilienfeld, June 20, 1916, there are disclosed a series of alkyl ethers of cellulose. Certain of these are practically insoluble in'water, and my invention'is particularly applicable to others having that property, although not limited to them. Such ethers form strong and useful solutions in mixtures of methyl acetate and methyl alcohol. Nevertheless it is sometimes desirableto reduce the viscosity of such solutions, in order to regulate them for film manufacture, without substantially diluting them.

I have discovered that such regulation of the viscosity may be effected by adding small amounts of phenyl benzonate to the mixture of methyl acetate and methyl alcohol. Phenyl benzonate by itself does not have as much solvent action on cellulose ether as a mixture of methyl alcohol and methyl acetate. The addition of small amounts of it to such mixture would not therefore, be expected to have a lowering effect on the viscosity of the resulting solution of cellulose ether. But an amount of phenyl benzonate equal to one-seventieth of the weight of the methyl acetate and methyl alcohol mixture, for example, will lower the S. FAnRow,

.usual way.

Application filed July 7, 1922. Serial No. 573,469.

viscosity of a thick solution of cellulose ether in such mixture by about 15 to 20 per cent. This surprising action indicates that the phenylbenzoate has a strong latent solvent power which is made active under these circumstances. I

The proportions may vary considerably, but I findthat a solution containing 1 part by weight of phenyl benzoate to 70 parts of the mixture of methyl acetate and methyl alcohol is particularly useful, yet any dilution of the solution is negligible. mixture of the acetate and. alcohol may vary also, but I prefer to use the ratio of 90 parts by Weight of weight of the latter.

Thefamount of cellulose ether dissolved in the complete viscosity-regulating solvent may, of course, be considerably varied. By way of example, I may dissolve 1 part of water-insoluble ethyl cellulose in from 3 to 6 parts of the mixed solvent.

It will be noted that some of the phenyl benzoate remains in the finished film formed by flowing or depositing-such dopes in the Other substances which impartadditional suppleness or incombustibility,

or other qualities to the film may be added to the above solutions or dopes, such moditying. agents being, for instance, triphenyl or tricresyl phosphate, camphor, monochlornaphthalene, etc.

The ingredients are of the ordinary commercial type sufficiently purified for the process of film manufacture, so as to give dopes yielding films having the proper relative freedom from color.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A composition of matter comprising cellulose ether dissolved in a mixture of methyl alcohol. methyl acetate and phenyl benzoate.

2. A flowable filmforming composition ramprising an alkyl ether of cellulose dissolved in a mixture of methyl alcohol, methyl acetate and phenyl benzoate, the weight of the latter being approximately one-seventieth the combined weights of the methyl acetate and methyl alcohol.

The

the former to 10 parts by 3. A composition of matter comprising a solution of 1 part by Weight of water-insoluble ethyl cellulose in from 3 to 6 parts of a mixture of methyl alcohol, methyl ace-.

5. As an article of manufacture, a flowed,

flexible, transparent film comprising water- 10 insoluble ethyl cellulose and phenyl benzoate.

Signed at Rochester, New York, this 30th day of June, 1922,

EDWARD S. FARROW, J R. 

